DNA and polymer physics: statistical properties and effect of confinement studied by Atomic Force Microscopy

Wednesday, 6 April 2016, at 11:15 in Y36 J33

The seminar will present how to use DNA of various topological forms (linear, circular and knotted DNA) in order to study polymer physics. On the other side, I will show the benefits of this approach for the study of DNA and its function inside the cell and what it can be gained from polymer physics. Examples will be presented for linear DNA of various lengths, circular DNA as isolated molecules and in concentrated forms, and knotted DNA. For these studies, Atomic Force Microscopy (AFM) images of DNA were analysed and interpreted using polymer physics concepts. It turns out that AFM images deliver a wealth of detailed data never available before and that now it is possible to compare theoretical predictions for linear, circular and knotted polymers with real polymers. The effect of confinement of DNA is demonstrated using nanochannels in which circular DNA of different lengths were introduced. The biological consequences of the confinement of DNA are discussed.